scholarly journals Pollution Free Chemical Reactions in a Fluidized Bed

2015 ◽  
Vol 1 (2) ◽  
pp. 27-34
Author(s):  
M Nagaraja ◽  
Idahosa Charles ◽  
R Sundaresan ◽  
R Natarajan
Keyword(s):  
Fluidized Bed ◽  
Chemical Reactions

Second-Law Analysis of Fluidized-Bed Steam Generators

1990 ◽  
Author(s):  
Gianni Bidini ◽  
Carlo N. Grimaldi ◽  
Giampaolo Manfrida
Keyword(s):  
Heat Transfer ◽  
Heat Release ◽  
Fluidized Bed ◽  
Chemical Reactions ◽  
Second Law ◽  
Solid Residue ◽  
Sensible Heat ◽  
Steam Generators ◽  
Second Law Analysis ◽  
Fluidized Bed Combustor

Direct and indirect exergy balances are applied to a simplified fluidized bed combustor. The major losses are calculated, including exergy from chemical reactions (combustion, calcination, and sulfation), heat transfer, and sensible heat release to the environment (ash and solid residue flows). The analysis is applied to atmospheric and pressurized fluidized bed combustors.

Erosion Mechanism of Platen Heating Surfaces in CFB

2012 ◽  
Vol 472-475 ◽  
pp. 2287-2291 ◽  
Author(s):  
Jing Hui Song ◽  
Tao Wang ◽  
Xiao Ying Hu ◽  
Chang Qing Dong
Keyword(s):  
Fluidized Bed ◽  
Chemical Reactions ◽  
Maximum Velocity ◽  
Two Dimensional ◽  
Solid Flow ◽  
Flow Models ◽  
Erosion Mechanism ◽  
Heating Surfaces ◽  
X 24 ◽  
The Right

A two-dimensional numerical gas-solid flow models without chemical reactions is developed to simulate gas-solid flow in the fluidized bed boiler through MFIX software. Platen heating surfaces is considered in the upper of the furnace. Considering that velocity and concentration are the most factor effecting on erosion, there are three main area suffered serious erosion: (1) There is a maximum velocity at the position ( X = 57 cm, Y= 60 cm) on the right side of the wall, which will produce serious impact and erosion. (2) In the vicinity of position (X = 57 cm, Y= 140 cm) will suffer serious impact and tear. (3) As to the platen heating surfaces, the lower part which connect with flow is slightly wear and impacted. While the velocity on the right part is relatively large, especially in the corner of position (X = 24 cm, Y= 147 cm) reach a maximum.

CFD Simulation of Pyrolysis of Lignite in a Downstream Fluidized Bed

2012 ◽  
Vol 457-458 ◽  
pp. 515-520 ◽  
Author(s):  
Yong Li Sun ◽  
Rong Zhang ◽  
Lv Hong Zhang ◽  
Ya Nan Zhang
Keyword(s):  
Fluidized Bed ◽  
Chemical Reactions ◽  
Coal Combustion ◽  
Cfd Simulation ◽  
Inert Gas ◽  
Combustion Model ◽  
Particle Track ◽  
Nitrogen Gas ◽  
Commercial Software ◽  
Injection Point

This paper works with the CFD simulation of the process of pyrolysis of lignite particles in a downstream fluidized bed, which actually means the particles would fall down from the injection point and escape the furnace from the bottom. The particle track is solved by using the Lagrangian approach, while the flow of the inert gas (nitrogen) is dealt with by the Eulerian approach. The heat transferred from the nitrogen gas to the surface of particle is computed by means of the famous Ranz-Marshall correlation. The chemical reactions are simulated using part of the coal combustion model inserted in the commercial software used.

scholarly journals Interactive graph dynamics for fuzzy autocatalytic set of fuzzy graph of type-3 for combustion process in a circulating fluidized bed boiler

2015 ◽  
Vol 11 (1) ◽  
Author(s):  
Hazwani Hashim ◽  
Sumarni Abu Bakar
Keyword(s):  
Fluidized Bed ◽  
Chemical Reactions ◽  
Transition Matrix ◽  
Circulating Fluidized Bed ◽  
Combustion Process ◽  
Fuzzy Graph ◽  
The Real ◽  
Real Process ◽  
Graph Dynamics ◽  
Type 3

Dynamical changes of chemical reactions which occurred during combustion process in Circulating Fluidized Bed boiler (CFB) has been modelled using adjacency matrix of Fuzzy Autocatalytic Set (FACS) of fuzzy graph type-3. Analysis of sequence of changes in the reactions at time t through Perron-Frobenious eigenvector (PFE) of the matrix in the Graph Dynamic Algorithm (GDA) shows that end-product of the combustion process in the CFB namely Water and Hydrogen is not really potrayed the real process.  Therefore, in this study, transition matrix of FACS is utilized to analyse the dynamical changes of the reactions and the GDA is modified and improvised and known as Interactive Graph Dynamics (IGD) is subsequently use to facilitate the analysis. The result shows that by using the transition matrix of FACS, the end-product of the combustion process in CFB is in accordance to the real process. Whilst the IGD is able to reduced computer running time as compared to the existing GDA. This paper describes the development of IGD and the analysis of sequence of changes of chemical reactions during combustion process in CFB by using transition matrix with the helped of MATLAB. 

XRD Studies on Transformation of Dolomite under CO2 and N2 Atmosphere

2020 ◽  
Vol 1010 ◽  
pp. 355-360
Author(s):  
Siti Sarahah Sulhadi ◽  
Maratun Najiha Abu Tahari ◽  
Salma Samidin ◽  
Wan Nor Roslam Wan Isahak ◽  
Muhammad Rahimi Yusop ◽  
...  
Keyword(s):  
High Temperature ◽  
Crystallite Size ◽  
Fluidized Bed ◽  
Chemical Reactions ◽  
Fluidized Bed Reactor ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Studies ◽  
Significant Chemical

In this study, dolomite was heated under CO2 and N2 gases using fluidized bed reactor from 85 °C to 835 °C. Dolomite under N2 atmosphere did not show any significant changes on its crystallite size, suggesting there is no significant chemical reaction. On the other hand, dolomite under CO2 atmosphere shows no significant changes on its crystallite size until it reaches high temperature (> 800 °C) where MgO started to be observed in X- ray diffraction. This shows that few chemical reactions started to happen in this reaction condition.

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